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Biomedical subjects

R H Barnes

Publications and source records attributed to R H Barnes.

At least 19 recordsLinked to original sources
PubMed1977

Early protein malnutrition in the rat: behavioral changes during rehabilitation.

Behavioral development was studied in 2 groups of rats during the postweaning period. Pups were selected from litters nursed by dams fed either a standard protein (25% casein by weight) or a low protein diet (12% casein) during lactation. Two pups from each litter were housed together and fed the control diet throughout rehabilitation. Behavioral observations were made by repeated time-lapse photography at 5-day intervals. Differences in home cage behavior were observed at the onset of rehabilitation in the postnatally malnourished rats. Increased feeding behavior was observed during the 1st week of rehabilitation. Locomotor behavior was depressed during the rehabilitation period in the experimental animals. Climbing activity, however, was significantly greater. Self-grooming activity was elevated throughout rehabilitation in post-natally malnourished animals. During the course of rehabilitation, the behavioral differences between the 2 groups gradually disappeared.

Animals↗
PubMed1977

Protein malnutrition induced during gestation: its effect on pup development and maternal behavior.

Repeated time-lapse photographic observations were used to examine the ontogeny of behavioral development in prenatally malnourished rat pups following birth. Pups born to dams receiving a low protein diet (7% casein by weight) were fostered at birth to well-nourished dams and behavioral observations were made at 4-day intervals. Dams nursing gestationally malnourished pups were observed to spend more time in the nesting area with their pups towards the end of lactation. Moreover, the behavioral development (locomotion, feeding, and rearing and climbing activity) of gestationally malnourished offspring was depressed when compared to their controls. The results indicate that prenatal undernutrition alters the behavioral development of the offspring and maternal behavior of the dam in a manner which reduces the exposure of the pup to the immediate environment.

Animals↗
PubMed1977

Effect of different postnatal periods of protein-energy malnutrition in young rats upon subsequent protein utilization.

Previously it had been shown that rat pups, malnourished during the 3-week suckling period and the nutritionally rehabilitated for about 30 weeks, showed an increase in the efficiency of dietary protein utilization of the protein was fed at a less than optimal level and if the protein was of poor nutritional quality (J. Nutr. 103, 273, 1973). The present study extends this observation to growing rats malnourished during the first 3 weeks of life and then rehabilitated with a 25% casein diet for 4 weeks. The test proteins were casein, fed at a level of 12%, and wheat gluten, at a level of 25%. Efficiency of nitrogen retention was greater for both proteins in rats previously malnourished than for control, non-malnourished rats. Malnutrition was then imposed on rats malnourished by feeding a low protein diet either during the first 4 weeks postweaning or from the 7th to 11th week of life. After these periods of malnourishment, the rats were rehabilitated for 4 weeks and efficiency of utilization measured for both casein and wheat gluten fed at 10% of the diet. No change in utilization was found for either protein fed to rats rehabilitated from either of these periods of malnutrition.

Animals↗
PubMed1977

Comparative contributions of dietary protein quality and quantity to growth during gestation, lactation and postweaning in the rat.

The growth promotion by feeding purified diets containing 25%, 12% or 7% of either casein or wheat gluten (W.G.) and the supplementation value of adding cystine to the low casein diets, and lysine or lysine plus threonine to the wheat gluten diets ascertained in rats by comparing the weight achieved at birth, after 3 weeks suckling or 4 weeks postweaning. Birth weight was depressed by 30% with 7% casein; by 20% with 7% W.G.; by 15% with 25% W.G. compared to controls and there was no change when lysine alone was added to 7% W.G. Addition of lysine plus threonine to 7% W.G., lysine to 25% W.G. and cystine to 7% casein increased birth weight. The weight gain of dams reflected birth weight of pups in most cases. Weaning weight was depressed by 60% with either 12% casein or 12% W.G., and by 40% with 25% W.G. compared to controls. Addition of cystine to 12% casein and lysine to 25% W.G. increased the weaning weight slightly. Addition of lysine, lysine plus threonine or lysine plus glutamic acid (G.A.) to 12% W.G. had no effect on weaning weight. Maternal weight loss was decreased by amino acid supplementation of the diet. Four-week postweaning body weight was equal to the control when cystine was added to 12% casein and lysine was added to 25% W.G. Addition of lysine to 12% W.G. improved the growth rate, and addition of lysine plus threonine further improved the growth rate. Food intake was not decreased by protein deficiency during gestation. Food intake was significantly lowered by protein deficiency during both lactation and postweaning, however, supplementation of amino acid partially restored food intake to normal levels.

Animal Nutritional Physiological Phenomena↗
PubMed1976

Effect of postnatal dietary protein and energy restriction on exploratory behavior in young pigs.

Three-week-old pigs were subjected to dietary energy or protein restriction so as to prevent weight gain over a period of 8 weeks. During the last week of restriction their responses to a novel object introduced into an exploratory test situation were measured. The malnourished pigs exhibited indifference to the object, taking longer to make contact with it, spending less time playing with it, but not showing evidence of fear or avoidance of the object or the area in which it was located. Following 6 weeks of nutritional rehabilitation, the previously malnourished pigs again displayed less approach behavior to the novel object than controls, but the effect was substantially reduced. These observations are interpreted to support our hypothesis that a major mechanism through which early malnutrition produces long-term effects on behavior is by disturbing those behaviors required for gathering information from the environment.

Animals↗